The present invention relates to an angle adjustor, and more particularly, to an angle adjustor for a musical instrument.
It is desirable that the angular position of a musical instrument, such as a cymbal and a snare drum supported by a floor stand, a cymbal supported on a bass drum, or a tom-tom, be adjusted in accordance with the performer's preferences, physical features, etc. Once the angular position of a musical instrument is adjusted, it is desired that the musical instrument be stably supported during performance at the adjusted angle. U.S. Pat. No. 5,146,808 describes an angle adjustor 61, as shown in FIG. 9. The angle adjustor 61 includes a movable member 63, a fixed member 62, and a plurality of friction plates 64a and 64b. The movable member 63 is connected to a musical instrument, such as a cymbal. The fixed member 62 is connected to a main body of a stand. The plurality of friction plates 64 are arranged between the movable member 63 and the fixed member 62. In detail, two friction plates 64a are attached to the fixed member 62, and three friction plates 64b are attached to the movable member 63. The friction plates 64a and the friction plates 64b are alternately arranged. Each of the friction plates 64a and 64b has three teeth 65 on its outer circumference. The fixed member 62 and the movable member 63 have four teeth. The three teeth 65 of each of the friction plates 64a and 64b are engaged in grooves formed between the four teeth 66 of the corresponding one of the fixed member 62 and the movable member 63. The fixed member 62 and the movable member 63 are fixed to each other by a bolt 67 and a nut 68.
In the above angle adjustor 61, the nut 68 is loosened to enable the movable member 63 to rotate relative to the fixed member 62, and the movable member 63 is arranged at a desired angle relative to the fixed member 62. Then, the nut 68 is tightened so that the movable member 63 comes into contact with the fixed member 62 via the plurality of friction plates 64a and 64b. As a result, the musical instrument, which is connected to the movable member 63, is supported at the desired angular position.
However, in the adjustor 61, the positioning of the friction plates 64a and 64b relative to the movable member 63 and the fixed member 62 is performed by the engagement between the teeth 65 and the teeth 66. Thus, there may be a slight backlash produced at the position of engagement between the friction plates 64a and the movable member 63 and the position of engagement between the friction plates 64a and the fixed member 62. At such backlash positions, friction force produced by the friction plates 64a and 64b is not applied to the movable member 63 and the fixed member 62 no matter how tight the friction plates 64a and 64b are fastened to each another. This may slightly move the movable member 63, which is fixed to the fixed member 62. As a result, the musical instrument is not stably supported even after its angle has been adjusted.
U.S. Pat. No. 5,154,382 describes an angle adjustor 81 shown in FIG. 10 that solves this problem. The angle adjustor 81 includes a fixed member 82, a movable member 83, and a plurality of friction plates 84a and 84b, which are arranged between the fixed member 82 and the movable member 83. The plurality of friction plates 84a and 84b are tightened to one another and are fixed to the fixed member 82 by a bolt 87 and a nut 88. Additionally, tabs 85 extending from the friction plates 84a and 84b are received in slots 86 of the fixed member 82 and the movable member 83. The tabs 85 are pressed against side walls of the slots 86 by screws 89 to fix the friction plates 84a and 84b in the slots 86. The friction plates 84a and 84b are securely fixed to the corresponding one of the movable member 83 and the fixed member 82. This stably supports the musical instrument.
However, in the above angle adjustor 81, the screws 89 are oriented in the direction in which the movable member 83 rotates. When playing the musical instrument, a force that causes the movable member 83 to rotate may be applied to the screws 89 via the tabs 85 of the friction plates 84. This may loosen the screws 89. In such a case, the screws 89 cannot hold the tabs 85 in a fixed state. Thus, the movable member 83, which is fixed to the fixed member 82, may slightly move. As a result, the musical instrument, which has been adjusted to a desired angular position, may not be stably supported.
Further, in the adjustor 81, the movable member 83 is sandwiched by the fixed member 82. Thus, the fixed member 82 and the movable member 83 have different shapes. This complicates the manufacturing processes for the adjustor 81 and causes assembly of the adjustor 81 to be difficult.